A radio communication system including a radio base station and a radio terminal has been known. For example, a radio communication system, which is disclosed in patent documents (JP 2012-129646 A, WO 2011/093093 A1, JP 2013/521740 T, JP 2013/520088 T, and JP 2013-42339 A), includes a macro base station and a micro base station, a radio area of which is narrower than that of the macro base station. The micro base station is arranged within the radio area provided by the macro base station. Since, in the radio communication system, some radio terminals, among a plurality of radio terminals located within the radio area provided by the macro base station, are accommodated by the micro base station, a communication load can be dispersed.
Furthermore, in the radio communication system disclosed in the patent documents, the macro base station sets transmission powers of a plurality of different radio resources to be different from each other. Also, in the radio communication system disclosed in the patent documents, the macro base station punctures (or mutes) a specific resource element among the radio resources.
Also, in the radio communication system disclosed in the patent documents, the radio base station applies power boosting to a specific reference signal. The power boosting is to increase a transmission power of a resource element assigned to a reference signal by borrowing a power of a resource element different from the resource element assigned to the reference signal.